Low gamma nuclei (e.g. 31P, 13C & 23Na) MRI/MRSI offers an unmatched imaging modality in studying metabolism and physiology of the human system. Unfortunately, due to the low natural abundance of low gamma nuclei, this promising technique suffers from the low SNR and long acquisition time. Recent breakthroughs in hyperpolarized 13C methods have demonstrated an unprecedented ~50,000-fold SNR gain in-vivo, which provides a great new opportunity for MR metabolic imaging. However its fast signal decay (~1 minute) is a challenge for applying this revolutionary technique to in-vivo applications. With the proven advantages of the intrinsically high sensitivity and fast acquisition, high-field parallel imaging would be a solution to alleviate SNR and long acquisition-time problems. However, implementation of the high-field parallel imaging to low-gamma nuclei in human is hindered by design difficulties for the required multichannel double- tuned transceiver arrays due to the interaction between the different nuclei channels, degraded Q factors, increased cable-resonance and interference of two fields with different frequencies, besides the challenges in a single-tuned proton transceiver array, such as the radiation losses and decoupling difficulties. In fact, the lack of the transceiver arrays has become a major hindrance for low-gamma nuclear high-field parallel MRI/MRSI, and there is a pressing demand for developing robust techniques for design techniques to facilitate the low- gamma nuclei detection, especially for hyperpolarized 13C, using high-field parallel MR imaging in human. Therefore, we propose a comprehensive project for developing multichannel double-tuned transceiver arrays based mainly on the recently developed common-mode and differential mode (CMDM) method with the microstrip transmission (MTL) technique. The major goals of this project are focused on 1) development of general design techniques through proposed array projects with immediate in-vivo applications at UCSF, 2) establishment of theoretical and numerical models to understand and simulate the multichannel double-tuned transceiver arrays in decoupling, dual-frequency interaction, EM fields, resonant frequencies, and SAR, and 3) validations of proposed transceiver array technology with performance comparison, safety assessment and real patient demonstration. The proposed double-tuned transceiver array techniques provides unmatched advantages of high sensitivity, improved isolation between two frequencies, sufficient decoupling, capability of dense-spaced array design, improved Q-factors, and easy construction. This research will provide a robust solution to design of multichannel double-tuned transceiver array for low-gamma nuclear high-field parallel imaging and result in significant technological advances in multinuclear transceiver array engineering. These developments will be critical to the future success of low-gamma nuclear high-field parallel imaging for metabolic and physiological investigations in preclinical and human studies. PUBLIC HEALTH RELEVANCE: The successful outcome of the proposed project will advance the low-gamma nuclear MRI/MRSI with high sensitivity and speed for studying metabolism and physiology in health and diseased conditions in human non- invasively, and make the low-gamma nuclear, in particular, hyperpolarized 13C, MRI/MRSI clinically practical. The research effort will have an immediately impact to better understanding of human physiology, pathology, metabolism and diseases, at molecular level possibly.